REN Shan-ling, ZHANG Jia-hua, L&#220; Shao-zhe, CAO Li-xin, SONG Hong-wei, HUANG Shi-hua. Dynamics of Luminescence Enhancement of ZnS:Mn<sup>2+</sup> Nanoparticle Dispersed in PVB Film[J]. Chinese Journal of Luminescence, 2002,23(5): 451-455
REN Shan-ling, ZHANG Jia-hua, L&#220; Shao-zhe, CAO Li-xin, SONG Hong-wei, HUANG Shi-hua. Dynamics of Luminescence Enhancement of ZnS:Mn<sup>2+</sup> Nanoparticle Dispersed in PVB Film[J]. Chinese Journal of Luminescence, 2002,23(5): 451-455DOI:
nanoparticle synthesized by chemical colloid method has been dispersed into PVB ethanol colloid to form organic film. From the emission spectra before and after UV 290nm irradiation
the luminescence peaked at 580nm of Mn
2+
4
T
1
→
6
A
1
transition has a higher enhancement than that ever reported under UV 300nm excitation. The emission spectra
excitation spectra and time-dependent luminescence growth were employed to determine the dynamics of the irradiation-induced luminescence enhancement effect (RILE). The excitation spectra after irradiation showed that there are two excitation peaks
which are corresponding to the 1S and 1P energy state of ZnS
respectively. The 1S excitation peak's shift to the high energy compared with the bulk materials induced by the quantum confine effect
indicates that the average size of nanoparticles is around 3nm by the theory of Effect Mass Approximation (EMA). With the UV irradiation
the shape of excitation spectra changed.The original 1P excitation peak grows more rapidly than the 1S excitation peak and get a higher value when the increment came to saturation. Dynamics of luminescence is investigated. We consider that surface state can quench the luminescence of Mn
2+
. With the irradiation
the surface state decreases and therefore luminescence of Mn
2+
increases. By fitting the experimental data
we find that the relaxation rate from 1P to quenching center has a linear relation with that from 1S to quenching center. We conclude that both 1P and 1S state can relax to quenching center. The enhancement is stable because the reduction of quenching centers is irreversibility. The sample has the same RILE effect after exposure to the natural light
so it can used as a new type of material to measure the dosage of UV irradiation.